Complications of immuno-oncology care: what urologist should know

OBJECTIVES

To provide a practical review of immune-related adverse events (irAEs) that may be encountered in uro-oncology patients.

PATIENTS AND METHODS

We conducted a literature review of studies reporting irAEs including articles published through September 2023 for uro-oncology patients and the potential relevancy for the practicing urologist.

RESULTS

Immunotherapy has revolutionised cancer treatment, extending its impact to urological malignancies including for patients with urothelial, kidney, and prostate cancers. Immuno-oncology (IO) compounds have achieved measurable and durable responses in these cancers. Urologists, choosing to administer or co-manage IO patient care, should be prepared to understand, evaluate, and treat irAEs. This review discusses the spectrum of irAEs that can be encountered. Ongoing trials are exploring the use of immunotherapy at earlier stages of uro-oncological diseases, thus underscoring the evolving landscape of urological cancer treatment. Paradoxically, some data suggests that the occurrence of irAEs is associated with improved oncological outcomes.

CONCLUSIONS

Immune-related AEs, while manageable, may be life-threatening and require lifelong therapy. A thorough understanding of AEs and toxicity of a novel drug class is imperative.

Influence of lamina propria invasion extension on T1 high-grade non-muscle-invasive bladder cancer in patients undergoing BCG or radical cystectomy

OBJECTIVE

To evaluate the prognostic value of T1 substaging in patients treated with bacillus Calmette-Guérin (BCG) or immediate radical cystectomy (iRC).

MATERIALS AND METHODS

We performed an institutional review board-approved retrospective study analysing non-muscle-invasive bladder cancer (NMIBC) patients with pT1 disease treated with either BCG or iRC between 2000 and 2020. Lamina propria (LP) invasion characteristics were extracted from the pathology report. The Kaplan-Meier method was used to calculate overall survival (OS), cancer-specific survival (CSS) and metastasis-free survival (MFS). Multivariable Cox models were used to determine the association between progression-free survival (PFS) and characteristics in the BCG cohort. A logistic regression model explored the relationship between T1 substaging and upstaging to >pT2 at iRC.

RESULTS

A total of 411 T1 high-grade patients were identified. LP invasion characteristics were as follows: not specified: 115 (28%); focal/superficial (F/S): 147 (35.8%); and extensive/multifocal (E/M): 149 (36.2%). Overall, 303 patients (73.7%) received BCG, and 108 patients (26.3%) underwent iRC. The median (interquartile range) follow-up was 53 (32-96) months. Patients with E/M LP invasion were significantly more likely to undergo iRC (34% vs. 19%; P = 0.003). Patients with E/M LP invasion showed poorer MFS and CSS compared to those with F/S LP invasion when treated with BCG but not when treated with iRC. Among BCG-treated patients, progression occurred in 41 patients and E/M LP invasion was independently associated with progression after BCG (hazard ratio 5.3, 95% confidence interval [CI] 2.2-13.1; P < 0.001). T1 substaging was not associated with upstaging at RC (odds ratio 3.15, 95% CI 0.82-12.12; P = 0.095).

CONCLUSIONS

Extensive/multifocal LP invasion was associated with poor PFS, MFS and CSS in patients treated with BCG. T1 substaging provides valuable prognostic information and should be reported in pathology reports.

Using a Multi-pronged Behavioral Intervention to Standardize Antibiotic Prophylaxis at the Time of Foley Catheter Removal After Radical Prostatectomy

OBJECTIVE

To identify antibiotic prescribing patterns at the time of foley catheter removal after radical prostatectomy and implement a multi-pronged behavioral intervention to standardize antibiotic use.

METHODS

This was a single-institution study examining the prescribing of antibiotics at the time of foley catheter removal after radical prostatectomy. Pre-intervention data were collected retrospectively to establish baselines for antibiotic prescribing, patient characteristics, and urinary tract infection rates. A single dose of an oral antibiotic taken at the time of foley catheter removal was recommended as the standard antibiotic protocol. A multi-pronged behavioral intervention was used to encourage compliance with our protocol. Adherence to the protocol, quantity of antibiotics prescribed, and rate of urinary tract infection were recorded prospectively. Durability of the intervention was evaluated during a post-intervention phase.

RESULTS

A total of 416 patients and 6 surgeons were included in the study. Accordance with the standardized antibiotic protocol was 59% in the pre-intervention phase and 91% in the intervention phase (P = .03). No patients in the intervention or post-intervention phase were prescribed more than one dose of an antibiotic. The rate of urinary tract infection did not differ across the study phases.

CONCLUSION

Implementation of a multi-pronged behavioral intervention resulted in a high rate of surgeon compliance with a standardized antibiotic protocol. This led to a significant reduction in antibiotic use with no change in the rate of urinary tract infection after foley catheter removal after radical prostatectomy.

Association of Age with Non-muscle-invasive Bladder Cancer: Unearthing a Biological Basis for Epidemiological Disparities?

BACKGROUND

Age disparity in patients with non-muscle-invasive bladder cancer (NMIBC) exists. Whether this is due to differences in adequate cancer care or tumour biology is unclear.

OBJECTIVE

To investigate age disparities in NMIBC using the Surveillance, Epidemiology, and End Results (SEER)-Medicare and UROMOL datasets.

DESIGN, SETTING, AND PARTICIPANTS

The SEER-Medicare data were used to identify patients with clinical stage Ta, Tis, and T1 NMIBC between 2005 and 2017 (n = 32 225). Using the UROMOL cohort (n = 834), age disparities across transcriptomic, genomic, and spatial proteomic domains were assessed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

For the SEER-Medicare data, multivariable competing-risk regression was used to examine the association between age and recurrence, progression, and bladder cancer-specific mortality (BCSM). For the UROMOL cohort, multivariable general linear model and multinomial logistic regression were performed to evaluate the association between age and tumour biology.

RESULTS AND LIMITATIONS

An analysis of the SEER-Medicare cohort revealed 5-yr recurrence rates of 55.2%, 57.4%, and 58.9%; 5-yr progression rates of 25.6%, 29.2%, and 36.9%; and 5-yr BCSM rates of 3.9%, 5.8%, and 11.8% in patients aged 66-70, 71-80, and ≥81 yr, respectively. After multivariable adjustment, age ≥81 yr was associated with a higher risk of recurrence (hazard ratio [HR] 1.07, 95% confidence interval [CI] 1.03-1.12; p = 0.001), progression (HR 1.32, p < 0.001), and BCSM (HR 2.58, p < 0.001). UROMOL2021 transcriptomic class 2a was most frequently observed in patients with advanced age (34.0% in ≥76 yr vs 21.6% in ≤65 yr; p = 0.004), a finding confirmed on multivariable analysis (risk ratio [RR] 3.86, p = 0.002). UROMOL2021 genomic class 3 was observed more frequently in patients aged ≥76 yr (4.9% vs 24.2%; p = 0.001). Limitations include the definitions used for recurrence and progression, which may lead to under- or overestimation of true rates.

CONCLUSIONS

Among SEER-Medicare patients with NMIBC, advanced age is associated with inferior oncological outcomes. These results reflect age-related molecular biological differences observed across transcriptomic and genomic domains, providing further evidence that innate tumour biology contributes to observed disparities in NMIBC outcomes.

PATIENT SUMMARY

Older patients with non-muscle-invasive bladder cancer have worse oncological outcomes than younger patients. Some of this age disparity may be due to differences in tumour biology.

Impact of age >70 years on oncological outcomes in patients with non-muscle-invasive bladder cancer treated with Bacillus Calmette-Guérin

OBJECTIVE

To evaluate the impact of age on oncological outcomes in a large contemporary cohort of patients with non-muscle-invasive bladder cancer (NMIBC) treated with adequate Bacillus Calmette-Guérin (BCG).

PATIENTS AND METHODS

We performed an Institutional Review Board-approved retrospective study analysing patients with NMIBC treated with adequate BCG at our institution from 2000 to 2020. Adequate BCG was defined as per United States Food and Drug Administration (FDA) guidelines as being receipt of at least five of six induction BCG instillations with a minimum of two additional doses (of planned maintenance or of re-induction) of BCG instillations within a span of 6 months. The study's primary outcome was to determine if age >70 years was associated with progression to MIBC cancer or distant metastasis. The cumulative incidence method and the competing-risk regression analyses were used to investigate the association of advanced age (>70 years) with progression, high-grade (HG) recurrence and cancer-specific mortality (CSM).

RESULTS

Overall, data from 632 patients were analysed: 355 patients (56.2%) were aged ≤70 years and 277 (43.8%) were >70 years. Age >70 years did not adversely affect either cumulative incidence of progression or HG recurrence (P = 0.067 and P = 0.644, respectively). On competing-risk regression analyses, age >70 years did not emerge as an independent predictor of progression or HG recurrence (sub-standardised hazard ratio [SHR] 1.57, 95% confidence interval [CI] 0.87-2.81, P = 0.134; and SHR 1.05, 95% CI 0.77-1.44, P = 0.749). Not unexpectedly, patients in the older group did have higher overall mortality (P < 0.001) but not CSM (P = 0.057).

CONCLUSION

Age >70 years was not associated with adverse oncological outcomes in a large contemporary cohort of patients receiving adequate intravesical BCG for NMIBC. BCG should not be withheld from older patients seeking for bladder sparing options.

Oncological Outcomes for Patients with European Association of Urology Very High-risk Non-muscle-Invasive Bladder Cancer Treated with Bacillus Calmette-Guérin or Early Radical Cystectomy

BACKGROUND

European Urology Association (EAU) guidelines recommend immediate radical cystectomy (early RC) for patients with very high-risk (VHR) non-muscle invasive bladder cancer (NMIBC), with bacillus Calmette-Guérin (BCG) recommended only for those who refuse or are unfit for RC.

OBJECTIVE

To describe oncological outcomes following BCG or early RC in a contemporary cohort of patients with VHR NMIBC (EAU criteria).

DESIGN, SETTING, AND PARTICIPANTS

Patients diagnosed with VHR NMIBC between 2000 and 2020 were identified from our institutional NMIBC registry.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcomes were overall survival (OS) and cancer-specific mortality (CSM). Secondary outcomes were the progression rate and high-grade recurrence (HGR) rate for patients receiving BCG.

RESULTS AND LIMITATIONS

We identified 235 patients with VHR NMIBC, of whom 157 (67%) received BCG and 78 (33%) underwent early RC. The median follow-up was 52.8 mo. OS and CSM rates were 80.2% and 5.3% in the BCG group, and 88.1% and 4.9% in the early RC group, respectively with no significant difference in OS (p = 0.6) or CSM (p = 0.8) between the two groups. Among the patients treated with BCG, 5-yr HGR and progression rates were 41.9% and 17.4%, respectively; 39 patients (25%) underwent delayed RC after BCG. No significant difference in CSM emerged when comparing patients treated with delayed RC (after BCG) with those undergoing early RC (p = 0.86).

CONCLUSIONS

Our findings suggest that intravesical BCG can be offered to patients as a resonable alternative to early RC for selected patients with VHR NMIBC.

PATIENT SUMMARY

We evaluated outcomes for patients with very high-risk non-muscle-invasive bladder cancer (NMIBC) treated with BCG (bacillus Calmette-Guérin) versus early surgical removal of the bladder and found no differences in survival. We conclude that BCG could be offered to selected patients with this type of bladder cancer as a reasonable alternative to early bladder removal.

International Bladder Cancer Group Intermediate-risk Nonmuscle-invasive Bladder Cancer Scoring System Predicts Outcomes of Patients on Active Surveillance

PURPOSE

We sought to determine if the International Bladder Cancer Group IR-NMIBC (Intermediate-risk Nonmuscle-invasive Bladder Cancer) scoring system can predict the requirement of delayed transurethral resection of bladder tumor in low-grade nonmuscle-invasive bladder cancer managed by active surveillance.

MATERIALS AND METHODS

We prospectively studied recurrent low-grade Ta/T1 nonmuscle-invasive bladder cancer patients managed with active surveillance with the following characteristics: low-grade papillary nonmuscle-invasive bladder cancer, ≤5 apparent low-grade nonmuscle-invasive bladder tumors, tumor diameter ≤1 cm, absence of gross hematuria, and negative urinary cytology. Subsequent transurethral resection of bladder tumor was offered to patients who no longer met the inclusion criteria or patient choice. The ability of the International Bladder Cancer Group IR-NMIBC scoring system to predict receipt of subsequent transurethral resection of bladder tumor was determined. Multivariable Cox proportional hazards analysis was used to determine factors associated with subsequent transurethral resection of bladder tumor.

RESULTS

A total of 163 patients with low-grade Ta/T1 nonmuscle-invasive bladder cancer were included for analysis. After a median follow-up of 33 months (IQR: 21-46), transurethral resection of bladder tumor was performed on 109 patients. At landmark time point of 24 months, patients with 0 risk factors were over 2-fold more likely to continue active surveillance compared to patients with ≥3 risk factors (59% vs 24%). Multivariable Cox regression suggested that the International Bladder Cancer Group IR-NMIBC scoring system was associated with subsequent transurethral resection of bladder tumor (1-2 risk factors [HR: 1.66, 95% CI: 0.96-2.90, P = .072], ≥3 risk factors [HR: 3.21, 95% CI: 1.70-6.09, P < .001]) after adjusting for age, T stage, and sex.

CONCLUSIONS

The International Bladder Cancer Group IR-NMIBC scoring system can predict the risk of subsequent transurethral resection of bladder tumor in patients with low-grade nonmuscle-invasive bladder cancer on active surveillance.

Bladder-sparing Treatment in Patients with Bacillus Calmette-Guerin-unresponsive Non-muscle-invasive Bladder Cancer: An Analysis of Long-term Survival Outcomes

Background

Data for bladder-sparing treatment (BST) in bacillus Calmette-Guerin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC) patients report short-term outcomes limited to 1-2 yr.

Objective

To assess long-term survival outcomes of BCG-unresponsive NMIBC patients treated with BST.

Design setting and participants

BCG-unresponsive NMIBC patients diagnosed between January 2000 and September 2021 from an institutional NMIBC registry were evaluated.

Intervention

Long-term survival outcomes for patients receiving BST, early radical cystectomy (RC), and delayed RC were compared.

Outcome measurements and statistical analysis

The primary endpoints were overall survival (OS) and cancer-specific survival (CSS).

Results and limitations

In total, 114 patients with a median follow-up of 71.2 mo (interquartile range: 32.6-132.2) were analyzed. There were no significant differences in OS (hazard ratio [HR]: 1.40, 95% confidence interval [CI]: 0.68-2.89, p = 0.4) or CSS (HR: 0.88, 95% CI: 0.22-3.55, p = 0.9) between patients undergoing early RC (n = 38) and BST (n = 76). At 60 mo, BST patients had a high-grade recurrence-free rate, muscle-invasive disease/metastasis progression-free rate, and avoidance of RC rate of 37%, 83%, and 58%, respectively. Current smoker status (HR: 4.44, 95% CI: 1.41-13.97, p = 0.011) was the only variable predictive of high-grade recurrence following a multivariable analysis. The median time to RC from BCG-unresponsive date was 2.1 and 11.7 mo for those undergoing early RC and delayed RC (after BST), respectively. Patients treated with early RC had a higher incidence of cT1 disease (53% vs 36%, p = 0.049) and lymphovascular invasion (LVI; 11% vs 0%, p = 0.011) compared to patients treated with BST. Survival outcomes were similar between groups: 10-yr OS-58% versus 50% (HR: 1.40, 95% CI: 0.68-2.89, p = 0.4), and 10-yr CSS-81% versus 85% (HR: 0.88, 95% CI: 0.22-3.55, p = 0.9).

Conclusions

An analysis of long-term survival of BCG-unresponsive NMIBC patients receiving BST suggests that it may be safe in patients without LVI and/or variant histology and nonsmokers. Survival outcomes for patients treated with BST may not be inferior to those receiving early RC.

Patient summary

Bladder-sparing treatment can be offered to appropriately selected patients who have bacillus Calmette-Guerin (BCG)-unresponsive non-muscle-invasive bladder cancer. Long-term outcomes may not be inferior to those for patients who opt for early radical cystectomy.

Insurance Type and Area Deprivation Are Associated With Worse Overall Mortality for Patients With Muscle-invasive Bladder Cancer

OBJECTIVE

To examine the association of area-level socioeconomic status, rural-urban residence, and type of insurance with overall and cancer-specific mortality among patients with muscle-invasive bladder cancer.

METHODS

Using the Pennsylvania Cancer Registry, which collects demographic, insurance, and clinical information on every patient with cancer within the state, we identified all patients diagnosed with non-metastatic muscle-invasive bladder cancer between 2010 and 2016 based on clinical and pathologic staging. We used the Area Deprivation Index (ADI) as a surrogate for socioeconomic status and Rural-Urban Commuting Area codes to classify urban, large town, and rural communities. ADI was reported in quartiles, with 4 representing the lowest socioeconomic status. We fit multivariable logistic regression and Cox models to assess the relationship of these social determinants with overall and cancer-specific survival adjusting for age, sex, race, stage, treatment, rural-urban classification, insurance and ADI.

RESULTS

We identified 2597 patients with non-metastatic muscle-invasive bladder cancer. On multivariable analysis, Medicare (hazards ratio [HR] 1.15), Medicaid (HR 1.38), ADI 3 (HR 1.16) and ADI 4 (HR 1.21) were independent predictors of greater overall mortality (all P < 0.05). Female sex and receipt of non-standard treatment were associated with increased overall mortality and bladder cancer-specific mortality. There was no significant difference in both overall and cancer-specific survival between patients who were non-Hispanic White compared to non-White or between those from urban areas, large towns, or rural locations.

CONCLUSION

Lower socioeconomic status and Medicare and Medicaid insurance were associated with a greater risk of overall mortality while rural residence was not a significant factor. Implementation of public health programs may help reduce the gap in mortality for low SES at-risk populations.

Utilizing a Questionnaire to Implement a Risk-Based Antibiotic Prophylaxis Protocol for Transrectal Prostate Biopsy

OBJECTIVE

To develop and evaluate a risk-based antibiotic prophylaxis protocol for patients undergoing transrectal prostate biopsy.

METHODS

We created a risk-based protocol for antibiotic prophylaxis before transrectal prostate biopsy. Patients were screened for infection risk-factors with a self-administered questionnaire. The protocol was implemented from January 1, 2020 to March 31, 2020. We compared patient risk-factors, antibiotic regimens, and 30-day infection rates for patients undergoing transrectal prostate biopsies during the intervention and for a 3-month period before the intervention.

RESULTS

There were 116 prostate biopsies in the pre-intervention group and 104 in the intervention group. Although there was no significant difference in the number of high-risk patients between the two groups (48% vs 55%; p=0.33), the percentage of patients treated with augmented prophylaxis decreased from 74% to 45% (p=0.03). The duration of antibiotic administration and the median number of doses prescribed also decreased significantly. Despite significant decreases in antibiotic use, there were no differences in infection rates (5% vs 5%; p=0.90) or sepsis rates (1% vs 2%; p=0.60).

CONCLUSION

We developed a risk-based protocol for prophylactic antibiotics before prostate biopsy. The protocol was associated with less antibiotic use but did not lead to an increase in infectious complications.

A government mandated consent safely reduces opioid utilization for major pediatric genitourinary surgeries

INTRODUCTION

We describe the effect of a state mandated opioid consent on opioid utilization and multimodal pain use for major pediatric genitourinary surgeries.

METHODS

All patients who underwent an inpatient pediatric genitourinary surgery at the Children's Hospital of Pittsburgh between August 2015 and February 2020 were identified. Inpatient and outpatient multimodal pain control utilization were assessed. Delayed prescriptions or emergency department visits within 30 days were identified and when applicable referenced against National Surgical Quality Improvement Program data.

RESULTS

After accounting for a 6-month transition period following policy implementation, 462 major pediatric genitourinary procedures were identified. The frequency of discharge opiate prescriptions decreased from 68.4% prior to the transition period to 10.7% afterward(p<0.001). Morphine milligram equivalents per prescription decreased from 75(IQR 45-150) to 45(IQR 22.5-75)(p<0.001). The rate of delayed non-opioid analgesic prescriptions (6.6% vs 7.4%), delayed opioid prescriptions (1.5% vs 0.3%), or emergency department visits (11.8% vs 12.6%)(p = 0.809) remained unchanged. Data agreed with National Surgical Quality Improvement Program data in 98.5% of cases. After excluding one surgeon who departed after the transition period, regional block utilization did not change from 61/115(53%) to 147/320(45.9%)(p = 0.425).

CONCLUSIONS

A state mandated opioid consent safely reduced opioid utilization for most major pediatric genitourinary surgeries.

LEVEL OF EVIDENCE

Level III.

Associations Between Female Sex and Treatment Patterns and Outcomes for Muscle-invasive Bladder Cancer

OBJECTIVE

To investigate the association of female sex with the selected treatment for patients with nonmetastatic muscle-invasive bladder cancer. Sex is a known independent predictor of death from bladder cancer. A potential explanation for this survival disparity is difference in treatment pattern and stage presentation among males and females.

MATERIALS AND METHODS

Using the surveillance, epidemiology, and end results-medicare data set, we identified 6809 patients initially diagnosed with nonmetastatic muscle-invasive bladder cancer between 2004 and 2014. We fit multivariable logistic regression and Cox models to assess the relationship of sex with treatment modality and survival adjusting for differences in patient characteristics.

RESULTS

Of the 6809 patients with nonmetastatic muscle invasive bladder cancer, 2528 (37%) received a radical cystectomy while 4281 (63%) received an alternative bladder sparing intervention. Women were significantly more likely to receive a cystectomy (odds ratios [OR] 1.39; 95% confidence intervals [CI] 1.20-1.61), present at an older age with less comorbidities compared to men (P <.001). Women were also found to have worse bladder cancer-specific survival (CSS) than men (hazard ratio [HR] 1.18; 95% CI 1.05-1.32), no difference in overall survival (OS) (female HR 0.93; 0.86-1.01) and lower mortality from other causes (HR 0.78; 95% CI 0.70-0.86). There were no differences in OS and CSS by sex in patients with stage pT4a.

CONCLUSION

Female sex predicted more aggressive treatment with radical cystectomy yet worse cancer-specific survival than males. This sex disparity in CSS reduced the known OS advantage observed in women.

Abstract 5470: IKK-epsilon supports anchorage independent growth via alternative NF-kB signaling in triple-negative breast cancer

Metastatic breast cancer carries a poor prognosis despite the success of newly targeted therapies and treatment options remain especially limited for the subtype of triple negative breast cancer (TNBC). Several signaling pathways, including NF-κB, are altered in TNBC. Given that ΙΚΚε behaves as an oncogene in breast cancer we hypothesized that IKKε regulates classical or alternative NF-κB signaling to control diverse oncogenic functions in TNBC. Vector expression and RNA interference were used to investigate the functional role of IKKε in triple-negative breast cancer cells. Viability, protein expression, NF-κB binding activity, invasion, anoikis, and spheroid formation were examined in cells expressing high or low levels of IKKε in conjunction with alternative NF-κB p52 RNA interference or MEK inhibition. Our data show that p52 protein levels and binding activity are inversely proportional to ΙΚΚε. Moreover, knockdown of IKKε leads to increased expression of p52 and the p52-regulated gene CXCL1. This interaction was confirmed by CHiP-PCR experiments showing increased binding of p52 in the CXCL1 promoter of cells with IKKε knockdown relative to control. We further found that IKKε and MEK were required for growth in anchorage supportive conditions whereas p52 was required in anchorage resistant conditions. Western blots confirm diminished IKKε expression and enhanced p52 processing in anchorage resistant conditions relative to anchorage supportive conditions. In this model, IKKε and MEK cooperate to support growth of cancer cells in the attached, anchored environment, whereas p52 is required for growth in unattached 3-D environment. These studies reveal novel information about the role of IKKε in TNBC and highlight the adaptability of NF-κB signaling in maintaining cancer cell survival under different growth conditions. Current studies are underway to clarify the mechanism of IKKε regulation of p52. A better understanding of the diversity of NF-κB signaling may ultimately improve the development of novel therapeutic regimens for TNBC.

Citation Format: Carrie D. House, Valentina Grajales, Michelle Ozaki, Elizabeth Jordan, Helmae Wubneh, Danielle Kimble, Marianne Kim, Christina M. Annunziata. IKK-epsilon supports anchorage independent growth via alternative NF-kB signaling in triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5470.

IΚΚε cooperates with either MEK or non-canonical NF-kB driving growth of triple-negative breast cancer cells in different contexts

BACKGROUND

Metastatic breast cancer carries a poor prognosis despite the success of newly targeted therapies. Treatment options remain especially limited for the subtype of triple negative breast cancer (TNBC). Several signaling pathways, including NF-κB, are altered in TNBC, and the complexity of this disease implies multi-faceted pathway interactions. Given that IKKε behaves as an oncogene in breast cancer, we hypothesized that IKKε regulates NF-κB signaling to control diverse oncogenic functions in TNBC.

METHODS

Vector expression and RNA interference were used to investigate the functional role of IKKε in triple-negative breast cancer cells. Viability, protein expression, NF-κB binding activity, invasion, anoikis, and spheroid formation were examined in cells expressing high or low levels of IKKε, in conjunction with p52 RNA interference or MEK inhibition.

RESULTS

This study found that non-canonical NF-κB p52 levels are inversely proportional to ΙΚΚε, and growth of TNBC cells in anchorage supportive, high-attachment conditions requires IKKε and activated MEK. Growth of these cells in anchorage resistant conditions requires IKKε and activated MEK or p52. In this model, IKKε and MEK cooperate to support overall viability whereas the p52 transcription factor is only required for viability in low attachment conditions, underscoring the contrasting roles of these proteins.

CONCLUSIONS

This study illustrates the diverse functions of IKKε in TNBC and highlights the adaptability of NF-κB signaling in maintaining cancer cell survival under different growth conditions. A better understanding of the diversity of NF-κB signaling may ultimately improve the development of novel therapeutic regimens for TNBC.

Abstract 1955: IKKϵ maintains MEK activation and suppresses non-canonical NF-κB signaling in triple-negative breast cancer

Metastatic breast cancer carries a poor prognosis despite the success of newly targeted therapies. Treatment options remain especially limited for the subtype of triple negative breast cancer (TNBC). Several signaling pathways, including NF-κB, are altered in TNBC, and the complexity of this disease implies multifaceted pathway interactions and compensatory signaling. We hypothesized that a subset of TNBCs expresses IKKϵ to promote a specific NF-κB signaling program that can enhance metastatic potential. Our data suggest that IKKϵ supports MEK activation and suppresses non-canonical signaling by the p52 NF-κB transcription factor. We found that NF-κB p52 expression is inversely proportional to activated MEK. We further demonstrate that IKKϵ and MEK cooperate to support viability and invasion potential under adherent conditions, whereas the p52 transcription factor supports viability under non-adherent conditions, underscoring the contrasting roles of these proteins. This study illustrates the diverse roles of NF-κB signaling components in TNBC, and highlights the adaptability of NF-κB in maintaining cancer cell survival under different microenvironments. A better understanding of the diversity of NF-κB signaling may ultimately improve the development of novel therapeutic regimens for TNBC.

Citation Format: Carrie House, Valentina Grajales, Helmae Wubneh, Danielle Kimble, Marianne Kim, Christina Annunziata. IKKϵ maintains MEK activation and suppresses non-canonical NF-κB signaling in triple-negative breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1955. doi:10.1158/1538-7445.AM2015-1955

IKK-ε coordinates invasion and metastasis of ovarian cancer

Inhibitor of IκB kinases (IKK) are key regulators of NF-κB signaling. Three IKK isoforms-α, β, and ε-have been linked to oncogenesis, yet the precise components of NF-κB signaling in ovarian cancer have not yet been dissected. We surveyed 120 ovarian cancer specimens for IKK-ε expression. Notably, cytoplasmic expression was elevated in metastatic lesions relative to primary tumors (P = 0.03). Therefore, we hypothesized that IKK-ε drives ovarian cancer metastasis. IKK-ε was identified previously as a breast cancer oncogene and was associated with poor clinical outcome in ovarian cancer. We now define an ovarian cancer-specific IKK-ε-regulated gene expression signature using stably expressed short hairpin RNA targeting IKK-ε. Pathway analysis of the signature indicated that IKK-ε regulates expression of genes involved in cell motility and inflammation. We further showed that IKK-ε depletion in metastatic ovarian cancer cell lines decreased growth, adhesion, and invasion. Consistently, human xenografts depleted of IKK-ε in mice showed decreased aggressiveness, whereas overexpression of IKK-ε in a less invasive ovarian cancer cell line increased metastasis in vivo. Taken together, these data provide evidence that IKK-ε is a key coordinator of invasion and metastasis programs in ovarian cancer. Inhibition of IKK-ε signaling thus emerges as a viable therapeutic strategy in women whose ovarian cancer shows aberrant activation of this pathway.